Actual power consumption (active power) caused by a load such as an electronic apparatus or the like, can be obtained from a product of apparent power and power factor.
Information related to a phase error between a voltage and a current is required when obtaining the power factor.
For this reason, when obtaining the active power, a measurement is generally performed by directly connecting measuring terminals (or taps) of a measuring device to conductor wires of a cable.
Japanese Laid-open Patent Publication No. 2006-343109, Japanese Laid-Open Patent Publication No. 2006-184090, and International Publication Pamphlet No. WO2009/099032 are examples of related art.
However, when connecting the measuring terminals to the conductor wires of the cable, there are cases in which a power supply or the like of the load must be turned OFF for safety reasons or the like.